Indicator resetting system



June 22, 1954 MOLNAR INDICATOR RESETTING SYSTEM 8 Sheets-Sheet 1Original Filed Dec.

RESET SELECTOR RLSE INVENTOR. mm: MOLNAR ATTY.

I. MOLNAR INDICATOR RESETTING SYSTEM June 22, 1954 8 Sheets-Sheet 2Original Filed Dec. 30, 1948 INVENTOR. IMRE MOLNAR ATfY.

June 22, 1954 MOLNAR INDICATOR RESETTING SYSTEM 8 Sheets-Sheet 4Original Filed Dec. 30, 1948 INVENTOR. l M R E MOLNAR BY fl I,

ATTY.

June 22, 1954 MOLNAR INDICATOR RESETTING SYSTEM 8 Sheets-Sheet 5Original Filed Dec FIG.5

OFF-NORMAL INVENTOR. MOLNAR ATTY.

June 22, 1954 l. MOLNAR INDICATOR RESETTING SYSTEM 8 Sheets-Sheet 6Original Filed Dec.

FIG.6

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489 .iBBL 642 CID INVENTOR. IMRE MOLNAR ATTY.

June 22, 1954 MOLNAR INDICATOR RESETTING SYSTEM 8 Sheets-Sheet 8Original Filed Dec. 30, 1948 A u!- 0mm 080.5055 uo am .FGE OFF wnm mi o3I oo 02. xumzo wQE BY m

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Patented June 22, 1954 assign INDICATOR RESETTING SYSTEM Imre Molnar,Chicago, Ill., assignor to Automatic Electric Original application DLaboratories, Inc., Chicago, poration of Delaware 11]., a coreceinber30, 1948, Serial now Patent No. 2,647,249, dated July Divided and thisapplication February2, 1952, Serial No. 269,680

ables reservation clerks to register space reservation aboard aparticular vehicle of the carrier, which is to be operated over apre-determined course at some particular future time and date,

locallyat a common display panel; and in addition provides anovelapparatus whereby complete information of such reservations istransmitted to and is automatically and rapidly recorded at reservationoflices which are distant from such The display panel upon which suchinformation is registered contains, in case it is used by an air lineomce, a plurality of groups of space indicators, one-group for eachflight, there being a space indicator for each stop the air line isscheduled to make in the flight, the panel containing enough groups tocover all flights over a-periodof ten-clays. Suchspace indicators areadapted to indicate, by number or by some code arrangement'the number of.available spaces for passengers between the station represented by theindicator and the next succeeding scheduled stop of such air linecarrier. The indicators in each groupare preferably arranged in a row,the first indicator of a row representing the spaces available aboardthe carrier between the starting terminaland the first scheduled stop,the second indicator or" the same row representing the spacesavailable-between the first and second scheduled stops, and so forthuntil the last indicator of .the row represents theavailablespacesbetween the next to the last scheduled stop. and the final flightterminal. The .rows .of indicators representing flights on the-same dateare preferably mounted one. below the otherin a vertical column,

the vertical column then being labeled at the top by the date. Theverticalcolumns of flights are then mounted side by side, the order ofwhich being determined by the dates. Thedisplay panel is then capable offurther-expansion to report reservation information for as many days asis deemed desirable. A partof one'column of indicators is shown in Fig.10.

My eo-pending above mentioned application provides for the necessaryswitching-equipment whereby the space'indicatorscan be actuated by anyone of a plurality .of sets oroperating'keys sented by such indicator.

which are provided at a reservation clerks position. Operation of one ofthese sets of keys by a clerk will cause the switching apparatus toelectrically'connect such clerks position first to the equipmentassociated with the space indica torsof 'a particular date and then tothe space equipment associated with the space indicators of aparticularflight, after which time the clerk, by further operation of such keys,will actuate the space indicators corresponding to the stops between thecity of departure and the city of destination. The preferred arrangementis 'to have each space indicator visually display the number of spacesavailable for reservation in the carrier :for the portion of such flightrepre- Reservation of space represented as available by such indicatorsis thenindicated by subtracting a number of desired spaces from thepreviously displayed number of unreserved spaces.

An object of this invention is to provide, in -t system wherein aplurality of groups of indicators are to be reset to predeterminedpositions, means for automatically resetting each of the indicators inthe groups, the groups being reset automatically in order.

Another object of this invention is to provide, ina system wherein theindicators of one group of indicators in a plurality of groups are to bereset to .a pre-determined position, means for selecting the desiredgroupfrom among the plurality of groups and means for then automaticallyand simultaneously resetting all the indicators in the-selected group.

Another object of .this invention is to provide a system for resettingeach of a plurality of indicators from any miscellaneous position to anormal position automatically under control of a common control meansandfor then moving the indicators simultaneously and in unison from thenormal position to a predetermined position automatically undercontrolof thesame control means and for then stopping the indicatorssimultaneously when they reach the predetermined position.

Other objects and features ofthis invention will become apparent upona'perusal of the specification when taken inconjunction with theaccompanying drawings comprising Figs. 1 to 11, inclusive, in which:

Figs. 1 through 6, inclusive, show the circuits of a re-set converteranda reset selector which are preferably controlled from a supervisorsposition. Theselector switch is a Strowger type stepby-step, two-motionswitch having eight wipers,

Hi to I38, a vertical stepping magnet [93, a rotary stepping magnet I99,a release magnet l'l'i, vertical ofi-normal springs 29s (shown at theupper right of Fig. 2) and cam springs 253 which operate when the wipersare rotated to the eleventh position at any level. This switch has, inaddition, a vertical wiper 33E (Fig. 3) which is operated in a verticalstepby-step manner by the vertical magnet I90, during which motion thewiper engages successive vertical bank contacts associated therewith.

Fig. 7, which corresponds to Fig. 29 in the cited co-pending case, showsone of a number of reset connectors which are accessible to the resetselector. The connectors in turn have access to the space indicators.The connector switch is a Strowger step-by-step, two-motion switchhaving seven wipers, E3! to 13?, inclusive, a vertical magnet i156,rotary magnet I38, and a release magnet 739. The switch also includesinterrupter springs E26 which are operated by the vertical magnet 13%,vertical ofl-normal springs 124 which are operated on the first verticalstep of the wipers, cam springs 123 which are operated on the eleventhrotary step of the wipers at any level, and normal post springs N. P. S.which are operated only when the wipers step to the tenth level. Inaddition to the switch, the connector circuit includes a connect relay1H! which is actuated to connect impulse circuits to a group of fivespace indicators after they have been selected by the connector switch.

Fig. 9 shows a space indicator of the type which may be used in theinvention. It comprises a tens-digit wheel sit, a units-digit wheel 80!,a stepping magnet QM, off-normal springs 995 and cams 9H and M2. Cam 9!!is operated with digit wheel Bill and cam 952 is operated with digitwheel Sill. Each of the cams has one notch, the notches being inalignment while the display is being changed from to 99. The lever arm9B3, which is pivoted at point 952, bears against both cams and pivotscounterclockwise when the notches are aligned. The indicator is operatedin response to each deenergization of its stepping magnet 994 to displaya number one less than that previously displayed in one of any wellknown counter-operating manners. Normally, contacts 996 of the offnormal springs 2385 are open and contacts 9E3! are closed to connect thewindings of the stepping magnet 984 in series. However, when the displayis changed from 00 to 99, off-normal springs 8% are operated by arm 993to close contacts and open contacts 901. At contacts ear the lowerwinding of magnet 904 is disconnected from the upper winding and atcontacts see the upper winding is connected directly to groundpotential.

Fig. 8 shows the circuits for operating a group of two-digit spaceindicators. The indicators are accessible through the connector circuitsof both the reset apparatus, as shown in this application, and theinitial space reservation apparatus as shown in Fig. 26 of my saidcopending application.

Fig. 10 shows a portion of the display panel upon which are mounted thetwo-digit space indicators.

Fig. 11 shows the arrangement of the figures to complete the system.

Each level of the selector contact banks corresponds to a particulardate. And since there are ten levels in the selector switch, ten datesare provided for in this particular embodiment of the invention. Eachset of bank contacts in a selector bank level is associated with oneconnector, the connector having access to indicators on flights of thatparticular date only. Each set of connector bank contacts has access toup to five indicators. Where a flight requires the use of five or lessindicators, one set of connector bank contacts only is necessary toprovide for the indicators thereof. Where a flight requires six to tenindicators, inclusive, two sets of connector bank contacts are necessaryfor the flight; where eleven to fifteen indicators, inclusive, arerequired, three sets of connector bank contacts are needed for theflight, etc.

The resetting of the indicators is initiated from the supervisorsposition by operation of either the Date Reset key or the Flight Resetkey of Fig. 2. Operation of the Date Reset key conditions the convertercircuits for resetting all indicators of all flights on a particulardate. Operation of the flight Reset key conditions the convertercircuits for resetting only those indicators associated with a selectedflight on a particular date.

If the supervisor desires to reset all indicators on all flights on aparticular date he operates the Date Reset key and the selector switchwill then respond to a first digit dialed by the supervisor to step to aparticular level and thus select a particular date. The selector thenrotates automatically from bank contact set to bank contact set acrossthe level, stopping at each set to seize the associated connector whichthen in turn automatically steps vertically from level to level androtary in each level from bank contact set to bank contact set tothereby cause all the indicators associated with each connectoraccessible over the selected selector bank level to be reset by theconverter circuit to a predetermined position, the selector causing asignal to be given to the supervisor when it steps from the last contactset in the selected level.

If the supervisor desires to reset only those indicators associated witha particular flight on a particular date, he operates the Flight Resetkey. The selector responds to two digits dialed by the supervisor toselect a particular level of the selector and a particular bank contactset in the level and to seize the connector associated therewith, andthe connector then responds to two more digits dialed by the supervisorto select the indicators of a particular flight on that date, theconverter circuit then operating to reset these selected indicators.

The operation of the system will now be described in detail.

In order to reset all space indicators that correspond to a particulardate, the supervisor in charge operates the locking Date Reset key,which is shown at the top of Fig. 2, and then operates dial 236 toposition the wipers of the reset selector switch of Fig. 1 opposite thelevel of bank contacts corresponding to the particular date. Normally,no other manual operation is required to reset all space indicators ofthat date.

In response to the operation of the Date Reset key, ground is connectedthrough contacts 233 and 262 to holding conductor 289, and also atcontacts 233 the following circuit is closed to operate impulsing relay310: ground thru contacts 233, dial 236, conductor 231, contacts 308 andwinding of relay 3m to negative battery. The operating circuit of datereset relay 210 is completed from ground thru contacts 232, lower "tacts-3I3 an obvious circuit. is completed .for

illuminating the reset seize lamp 332. Relay'z'lfl prepares an impulsingcircuit for the vertical stepping magnet of the .reset selector atcontacts 27I, closes its locking circuit from ground thru contacts 232,lower winding of relay 2 70, contacts272 and upper winding of relay 2'70tonegative battery, and at contacts 275 prepares a circuitfortroublerelay 350 from conductor 277 thru contacts 275, conductor 273 and thelower winding of relay 35%! to negative battery.

Conductor 277 is connected to a conventional timing device (not shown)for applying ground pulse at pre-determinedintervals. In the event oftrouble that delays the resetting operation,

trouble relays 359 and 346 operate to give a trouble alarm. Uponoperating thru its lower winding responsive to the first timed groundpulse received over conductor 277, relay 358 closes its locking circuitfrom negative battery thru contacts 3i 3, upper winding of relay 350 andcontacts 35I to ground, and at contacts .352 connects conductor 353 tothe lower winding of relay 340. After a further time interval, ground isconnected to conductor'353 to operate relay 340. A locking circuit iscompleted from negative battery thru the upper winding of relay 34!),contacts 343 and contacts 3 of a manually operated switch to ground,lamp 346 is connected at contacts 342 to conductor 347 which isconnected to a source of ground pulses which cause the lamp to flash,and ground is connected to conductor 354 at contacts 34s for sounding analarm. The alarm continues until switch 345 is opened manually torelease relay 340.

Upon observing the illumination of reset seize lamp 332, the operatordials the number corresponding to the date of the flights of which theindicators are to be reset to thereby cause the wipers to be raised inthe reset selector banks to the level corresponding to the date. Inresponse to the operation of the dial, the previously traced circuit ofrelay M0 is interrupted intermittently to transmit impulses. At contacts3I3, the locking circuit of relay .350 is opened during each impulse torelease trouble relay 350 in event that it has previously operated. Atcontacts 3, an impulsing circuit to operate the vertical magnet I 90 tostep the wipers of the reset selector and to operate slowreleasingtransfer control relay I60 is completed from negative battery thrucontacts 3H, conductor 3E5, contacts 27!, 265 and .25I,.conductor '267,winding of relay I60, contacts I57 andthe winding of vertical steppingmagnet I00 to ground.

The pulsing or vertical magnet I90 raises the switch wipers I 3| to I98,inclusive, to the level corresponding to the number of digits in thefirst number dialed which in turn actuates vertical springs V. O. N. toclose contacts 290 on the first step of the wipers to preparea releasecircuit, and also raises vertical wiper 330 to the operating circuit ofslow-to-release impulsingcontrol relay I70.

Theengagement of any flight selector, that is, in a group correspondingto the same date as that of the selected level of the reset selector,delays the operation of the reset convertenuntil all flight selectors ofthat group become idle. For example, assume that the firstlevel of thereset selector has been selected, and that the flight selector of thereservation system, as shown in Fig. 26 of said co-pending application,-corre sponding to the first level is engaged, then, as relay I60releases shortly after the first series of impulses ceases, thefollowing circuit is completed to operate busy guard relay 250: negativebattery thru the lower winding of relay '250, conductor 257, contactsI64, conductor I66, contacts 287, conductor 258, contacts 306, verticalwiper 330, vertical bank contact 33I and conductor 395 of cable 334'toground at the flight selector. Upon operating, relay 250 opens a pointin the impulsing circuit at contacts 25I to prevent further stepping ofthe selector switch, closes a locking circuit for relay 200 at contacts253, opens the operating circuit of relays 300 and 32!! at contacts 25sand opens a point in the operating circuit of impulsing-control relay Iat contacts 255.

The locking circuit for relay 203 may be traced as follows: negativebattery thru theupperwinding of relay 2%, contacts HI and 253, conductor259, contacts 302, conductor 3H9, contacts 2!", conductor it? andcontacts m2 to ground. When all flight selectors corresponding totheselected date become idle, ground is removed from lead 395 andbusy-guard relay 250 releases to close the impulsing' circuit atcontacts 25I, to release transfer-control relay 280 and also to operaterelays 303 and 32B guently.

After the busy-guard relay250 releases, or if it does not operate, thereset converter operates automatically until all spacereservationindicators for the selected date are reset to display thenumber of seats initially available on all flights for thatdate. Jponreleasingafter the first series of impulses, transfer-control relayIfiltopens the operating circuit of slow-to-release transfer-controlrelay 206 at contacts I t! and also closes a circuit to energize thewindings of transfer relay i531 and closes the operating circuitofrelays 366i and 329 at contacts N52. The circuit for energizing thewindings of relay I50 in opposition may be traced from ground thru overcircuits traced subsecontacts I62, conductor i 57, contacts 20I,conductor I58, contacts i55, and from contacts I56 relays 32E and3ii0 tonegative battery.

The windings of relays 300 and 326 are chosen such that relay 325ioperates before relay 300. -Re1ay 32fi closes the following circuit tooperate level busy relay 3%: ground thru contacts "321,

' upper winding of relay 390, vertical contact 33I,

and lower winding of relay 250 to negative battery. The current flow inthis circuit is limited by the resistance of the upper winding of relay390 and is not suflicient to operate relay 250. Relay 390 connects itslower winding in series With the upper winding and negative battery atcontacts 39I and at contacts 302, which are connected to conductors and691, opens a point in the circuit of the wiper 2'163I of the flightselector shown in Fig. 26 of my co-pending application. Othcr contacts,such as contacts 393, open similar points in other flight selectorscorresponding to the selected level to prevent the regular selectorsfrom seizing connectOrs that have access to the particular datepreviously selected by the reset selector, Upon operating, relay 300, atmal e-before-break contacts 505 and 300, transfers the winding of theimpulsing relay from the circuit controlled by dial 236 to a circuitcontrolled by impulsing control relay I10, transfers the operatingcircuit of relays 300 and 320 from the ground at contacts I62 to theholding ground on conductor 289 at make-beforebreak contacts 304 and305, opens a point in the operating circuit of busy-guard relay 250 atcontacts 306 and prepares the operating circuit of impulsing-controirelay I at contacts 301.

Impulsing relay 3I0 is now maintained operated over the followingcircuit: negative battery thru the winding of relay 320, contacts 30!,conductor 322, contacts H2 and I21, conductor 323 and contacts 233 toground.

Upon releasing, transfer-control relay 200, at contacts opens thepreviously traced circuit for energizing the windings, of transfer relayI50 in opposition, and at contacts 204 closes the following circuit tooperate impulsing-control relay I10: negative battery thru relay I10,contacts I86 and IE3, conductor I14, contacts 204 and 255, conductor219, contacts 404, conductor 485 and contacts 301 to ground. When theinitial energizing circuit for the windings of relay I50 is opened atcontacts 205, the induced current in the closed circuit includingnegative battery thru the lower winding of relay 550, upper winding ofrelay 550, contacts I52 and resistor I58 changes the magnetic fieldsulficiently to cause the armature to close contacts I04. At contactsI54 the following circuit is completed for connecting the two windingsin series to aid each other in fully operating the transfer relay I50:negative battery thru the lower winding of relay I50, upper winding andinitially closed contacts I54 to ground on holding conductor 269. Uponcompleting its operation, relay I50, at contacts I52 and E53, transfersnegative battery and resistor I56 from its initial energizing circuit tothe upper winding of transfer relay I40, at contacts I55 and I56transfers an incomplete energizing circuit from relay I50 to relay I40,and at contacts I5? and ifii transfers the impulsing circuit fromvertical stepping magnet I90 to rotary stepping magnet I99.

Circuits have now been prepared for rotating wipers I9I to I93,inclusive, to engage the reset connector connected to the first bankcontacts of the selected level. Upon operating, relay I10 opens thepreviously traced circuit to release impulsing relay 3I0 at contactsI12. The circuit for energizing rotary magnet I99 to step the wipers thefirst step may be traced from nega- .tive battery thru contacts 3H,conductor 3I5, contacts 21I, 265 and 25I, conductor 261, relay I60,contacts I5I and. I48 and rotary'magnet I99 to ground. Relays I60 and200 operate as previously described. Upon operating, relay 200 atcontacts 204 opens the operating circuit of slowrelease relay I10. RelayI10 releases to close, at contacts I12, the previously traced operatingcircuit of impulsing relay 3I0. Relay 3I0 operates and opens the circuitto relay I60 and the rotary magnet I99. Relay I60, upon releasing,closes the following circuit for energizing in opposition the twowindings of transfer relay I40 which are connected in the mannerpreviously described for relay I: ground thru contacts I62, conductorI51, contacts 20I, conductor I60, contacts I and I45, through the lowerwinding of relay I40 to negative battery and through the upper windingof relay I40, contacts I42 and I53 and resistor I58 to negative battery.Release of relay I60 also opens the circuit to relay 200. Relay 200releases, opens the initial energizing circuit of relay I40 at contacts20I and closes again the operating circuit of relay I10 at contacts 204.When the initial energizing circuit of transfer relay I40 is opened,contacts I44 are closed in a manner similar to that described forcontacts I54 of relay I50 to complete the following circuit: negativebattery thru the lower winding of relay I40, upper winding, contacts I44and contacts I84 to ground on holding conductor 289. Upon completing itsoperation, relay I40 transfers the impulsing circuit from the rotarystepping magnet I99 of the reset selector to the vertical magnet 130 ofthe selected reset connector at contacts I48 and HI, transfers negativebattery and resistor I48 from upper winding of relay I40 to transferrelay I30 at contacts I42 and I43, and transfers the incomple'teenergizing circuit from relay I40 to relay I30 at contacts I45 and I46.

Circuits are now prepared for operating the selected reset connector,for example, Reset Connector of Fig. '7, that is connected to the firstbank contacts in the selected level. Relay I10 operates to open relay3I0 which releases to close the following circuit: negative battery thrucontacts 3, conductor 3I5, contacts 21I, 265 and 251, conductor 261,relay I60, contacts I5I, I4I, I3I and MI, wiper I9I, the first bankcontact of the selected level, conductor 10I, contacts II I, verticalstepping magnet 130 and rotary off-normal springs to ground. The singleimpulse transmitted to the vertical magnet positions rotary wipers 13Ito 131, inclusive, opposite their respective bank contacts of the firstlevel. Relay I60 operates on this pulse and closes relay 200. Relay 200operates, prepares the energizing circuit to the two windings of relayI30 at contacts 20I and opens the circuit to relay I10 at contacts 204.Relay I10 releases and closes relay 3) which operates to release thevertical magnet and relay I60. When relay I60 releases, the windings oftransfer relay I30 are energized over the circuit including contacts I35and I33, and, in response to the subsequent release of relay 200,operates fully over the circuit including contacts I34 in the mannerpreviously described for relays I40 and I50.

Relay I30 transfers the impulsing circuit from the vertical magnet 130to the rotary magnet 138 at contacts I3I and I32, opens points in itsinitial energizing circuit at contacts I33 and I35 and prepares thefollowing locking circuit which, at the conclusion of the next impulse,places the releasing of relay 200 under the control of busyguard relay250: negative battery thru the upper winding of relay 200, contacts 221and-".52, conductor 242, contacts I31, conductor 2 23 contacts 303,conductor 3&9, contacts 26L conductor l6! and contacts IE2 to ground.Relays Hi3, 3H), lfiil, and zoo operate again in the cycle previouslydescribed to send a single impulse over the circuit from negativebattery to contacts Ml, as previously traced, and now extended throughcontacts 532, I21, H13, wiper I92 and its respective bank contactconductor 102, contacts H3 and rotary magnet 733 to ground. Theoperation of the rotary magnet steps wipers 13| to I31, inclusive, tothe first set of bank contacts on the first level to establishcontrolling connections with a maximum of fivespace indicators asillustrated in Fig. 8.

Assuming that the selected group of indicators, i. e. those connected tothe first bank contact in the first level of the reset connector banlrs,are idle, the following circuit operations take place. When relay H63releases after the first rotary impulse to Rot. magnet 538, it opens theoriginal operating circuit to the lower Winding of relay 290 at contactslfii but closes a holding circuit to the upper winding of relay 266 atcontacts I62 via contacts It? to hold relay 20E) operated, and closesthe following operating circuit for relay HS and busy-guard relay 240:ground through the busy lamp associated with the selected indicators,for example, lamp 850 of Fig. 8, conductor 'l iii of cable Md and therespective bank contacts, wiper "its, relay Hi3, conductor 1m and itsterminating bank contact, wiper I91, contacts I28 and 83, conductor20.8, contacts 203, winding of relay 2%, conductor 2-0! and contactsHl'i to negative battery. Relay 24% operates and'closes a circuit fromground thru contacts 24!, conductor 65, contacts M4, .conductor 2.57:and lower winding of relay 250 to negative battery. Relay 25d operatesand opens the irnpulsing circuit at contacts 251, opens a point in theinitial energizing circuit of relays 3% and 326 at contacts 254, opensthe locking circuit of relay 2% at contacts 252 to cause its release,opens an additional point in the circuit of relay I76 at contacts 255,and closes the circuit at contacts 2523 for both the upper winding ofrelay 256 and the winding of cut-in relay Hill.

Connect relay lid operates, disconnects the vertical stepping magnet E36from its impulsing circuits at contacts ii i, disconnects the rotarystepping. magnet l3Bat contacts H3, opens a point in the circuitscontrolled by normal post springs N. P. S. at contacts H and H7, opens apoint in the circuit to the release magnet 139 at contacts H9, and ateach-of the contacts H2, lid, H6, H8, and its connects an iinpulsingcircuit to a different one of the space reservation indicators of Fig.8.

Assuming that the selectedgroup of indicators are already engaged by aregular connector, negative battery through a low resistance circuit ofthe regular converter is standing onthe circuit of busy lamp 859. Thislow resistance circuit to battery causes a reduction in the value of thecurrent which would normally flow in the above traced circuit to relaysHi3 and 240, and, when relay IE9 releases and closes the circuitto theserelays H6 and 2%, they remain unoperated. Relay 2% is held operatedthrough its upper winding from contacts I62 and in turn holds thecircuit to .relay llti'open at contacts 20 to-prevent further stepping,of thereset connector switch. The reset converter camps on the busygroup of indicators untilthe indicators are no longer engaged by aregular connector and then, in response to the removal of theabove-mentioned low resistance circuit, relay 24-9 operates, aspreviously described, to close the above-traced operating circuit torelay 256.

The locking circuit thru the upper winding of relay 2% may be tracedfrom negative battery thru the upper winding, contacts 256, conductor2'19, contacts 15M, conductor 585 and contacts 3! to ground and thecircuit to operate cut-in relay Hid may be traced from negative batterythru relay liiii, conductor H6 and contacts 25s to ground. Relay m9prepares an impulsing circuit for each of the five selected spaceindicators at contacts 662, let, 5%, iii? and H39, completes a circuittraced subsequently for operating pick-up relay 5% at contacts H2, opensthe energizing circuit of relay 2% at contacts H0, and at contacts iiimaintains a circuit from negative battery thru the winding of relay Hi3,conductor MS and busy lamp 3% to ground. This negative battery fromconductor Mt to bank contacts or" regular connectors renders theindicators busy thereto. Relay M53 releases.

Circuits for polarizing cut-oii relays 3%, 3m, 33E, 4%, and did, andalso for starting vibrator 530, which generates controlling impulses,are completed when the Date Reset key is first operated. A circuit forpolarizing the cut-oir relays may be traced from ground thru contacts233 and 262, conductor 289, resistor 3E2, polarizing windings of relays3%, did, and 33d, conductor 382 and upper windings or" relays tilt? andMil to negative battery. A circuit is also completed to operateimpulsing relays 55d and 556 as follows; ground on holding conductor 269thru contacts Edd, resistor 54?, lower winding of relay 55d and lowerwinding of relay 558 to negative battery. Relay 55B opens a point in anincomplete operating circuit for stepping magnet M558 at contacts 553;and relay 55d, at contacts 55.. and 552, and relay 55s, at contacts EM,582 and 563, open points in impulsing circuits that are later extendedto the five selected space indicator circuits by the previouslydescribed operation of cut-in relay Hit. Finally, in response to theground on conductor 28:3, a circuit for energizing the upper windings ofvibrator 538 is completed through contacts 553, contacts 525 andresistor 52? connected in parallel with resistor 528, and upper windingsto negative battery. The vibrator pendulum is attracted to close acircuit from negative battery thru contacts 53E and 523, lower windingof relay 52d and contacts 5i i to ground on holding conductor 289. Relay5% closes its locking circuit at contacts 52E from negative batterythrough the upper winding to holding conductor 282 opens its initialoperating circuit at contacts 523, compietes a circuit for energizingthe lower windings of the vibrator at contacts 522 and i 25, disconnectsstarting resistor 52'? from in parallel with resistor 528 at contacts528 to reduce the current flow in the upper windings of the vibrator,and completes the circuit for energizing slow-operating relay tilt atcontacts 52 8. Upon operating, relay 51d opens a further point in theinitial operating circuit of relay 5% at contacts 5H, prepares a circuitfor operating pick-up relay 5% at contacts 554, and at make contacts55-2 connects ground through contacts 524 to the circuit for holding theupper windings of the vibrator energized while disconnecting the holdingconductor 239 from this circuit at break contacts 513.

The magnetizing force of the lower windings of the vibrator, which wereclosed from contacts- 53! by operation of relay 520, is in opposition tothat of the upper windings to cause the pendulum to swing away from thecoils, closing contacts 532 and opening the circuit to the lowerwindings of the vibrator magnets. Opening of the lower windings causesthe pendulum to swing back to close contacts 53L This vibrator willcontinue to vibrate and cause alternate closing of contacts 531 and 532as long as relay 520 remains operated.

Shortly after cut-in relay I operates as previously described,slow-acting relay 200 releases in response to the previously describedoperation of relay 255. The circuit that is now completed for operatingpick-up relay 540 may be traced from negative battery connected to thevibrating pendulum thru contacts 532, M and 544, upper winding of relay540, conductor 545, contacts H3 and 082, conductor 485, contacts I4? andH2, conductor Ill and contacts 205 to ground on holding conductor 289.Relay 5 3-0, at contacts 55!, closes its locking circuit from batterythru its lower winding and contacts 505 to conductor 555 which isconnected to ground by the previously traced circuit, prepares animpulsing circuit for stepping magnet M550 at contacts 552, opens theinitial energizing circuits of impulsing relays 550 and 550 at contacts555 and closes a circuit to place the impulsing relays 550 and 555 undercontrol of the vibrator at contacts 503, and opens the circuit forinitially energizing relay 540 at contacts 504. The circuit forcontrolling the impulsing relays may be traced from battery on thependulum of the vibrator, contacts 532, 5M, and 543, upper windings ofrelays 550 and 550, conductor 485, contacts i4? and H2, conductor H1 andcontacts 205 to ground on holding conductor 289. The vibrator causesrelays 550 and 550 to pulse and in turn open and close contacts 55!,552, EN, 5st and 553 to send impulses over five individual circuits tothe magnets of the space reservation indicators of Fig. 8. For example,an impulsing cir cuit may be traced from negative battery thru impulsingcontacts 55!, conductor 555, contacts 552, conductor @554, operatingwinding of cut-off relay 3%, conductor 312, contacts 105, wiper I90,conductor E04, contacts H8, wiper T34, conductor I45 of cable 540, upperwinding of indicator magnet 800, contacts 8M and the lower winding ofthe indicator magnet to ground. Likewise, similar circuits may be tracedfrom contacts 552, 555i, 553, and 552, to operate space indicatormagnets 840, 820, 8i0 and 830, respectively. Impulses are sent over eachindividual impulsing circuit until both drums of the respectiveindicators display 9. For example, when the drums of the indicatorassociated with magnet 800 display 99, the cam spring 803 is actuated toclose contacts 302 and to open contacts 80!. At contacts 803, the upperwinding of indicator magnet 000 is connected directly to ground, and atcontacts 80! the lower winding is disconnected from the circuit. Thedecreased resistance and resultant increased current in this impulsingcircuit causes the operation of polarized cut-off relay 310 which, atcontacts 3', closes an operating circuit to its associated control relay050. Relay 450, at contacts 651, closes its locking circuit, opens thepreviously traced impulsing circuit to indicator magnet 800 at contacts452, and at contacts 453 closes a point in the chain circuit which isconnected to the winding of relay 410. The operating circuit of relay450 may be traced from negative battery thru the winding of relay 459,conductor 313, contacts 31 l, conductor 3' and contacts 50] to ground onholding conductor Z39. Likewise, when the indicators associated withmagnets M0, 820, 830 and 840 display 99, cutoff relays 360, 400, M0, and380, respectively, operate to close operating circuits at contacts 35LAM, HI, and 38!. If less than five indicators are connected to any setof contacts in the connector bank, the spare contacts are connected toground potential for operating the corresponding cut-off relays as soonas any of the five impulsing circuits are connected to the sparecontacts. Relays 460, 430, 420, and M5 operate to cut-on the impulsingcircuits, and at contacts 453, 433, 423, and 443, respectively, closethe operating circuit of slow-releasing relay 410. Each of the cut-offrelays 310, 350, 400, M0, and 300 releases after its associated controlrelay has operated. Upon operating, slow-release relay H0 closes itslocking circuit at contacts 41! and closes a circuit from ground onholding conductor 289 thru contacts 412, conductor 414 and winding ofslow-releasing relay 500 to negative battery. Relay 500, at contacts50!, opens the locking circuits of relays 420, 430, 440, 450, and 50,all of which release to connect again the five impulsing circuits to thesame group of five indicator magnets, and closes the following circuitto place stepping magnet M0 50 under the control of impulsing relay 550;negative battery thru winding of stepping magnet M650, conductor 642,and contacts 505, 553 and 542 to ground at holding conductor 289. Also,relay 500 prepares marking circuits through banks of switch $550 atcontacts 503 and 504.

The five indicators and the rotary switch S650 step together undercontrol of relays 550 and 560 until the selected indicators display thecorrect number of seats initially available in the particular flight.The numbers to be displayed on each set of indicators when they arefinally reset are determined by a marking circuit that is connected froma corresponding bank contact, for example, contact 15'! of the resetconnector of Fig. '7, to a contact in the banks of switch $550. Onecontact in one of the bank levels 655 to 659 and another contact in oneof the levels 652 to 555 is available for each number that can bedisplayed. The marking circuit for a set of indicators which is thefirst or intermediate set to be selected in a flight group includes acontact in one of the levels 555 to 659 while the marking circuit for aset of indicators which is the last, or only, set to be selected in aflight group includes a contact in one of the levels 652 to 555. When amarking circuit is completed through a contact in one of the levels 552to 655, relay 220 is operated to release the reset converter assubsequently described, but is effective to release the reset converteronly if the Flight Reset key rather than the Date Reset key has beenoperated. When the first impulse is transmitted to the indicator magnets800 to 840 and to magnet M550 from relays 550 and 560 after theoperation of relay 500, the display on each of the engaged indicators ischanged from 99 to 98 and the wipers of rotary switch S050 are steppedfrom the first or normal position to the second position, contacts ofoff-normal springs 650 closing on this first step to complete thefollowing circuit for operating relay 600: negative battery thru relay600, conductor 602, contacts 514, off- 13 normal springs 650 andcontacts593to ground. At contacts 69-! of'relay 690, a circuit is prepared foroperating relay 518 which at this time is short-circuited bytheoff-normal springs 65 E. During each one-half revolution of thewipers of switch $65!], a different one of the wipers 6% to 669,inclusive, is connected thru to relays 570 and fiilil in series and alsoa different one of the wipers 652 to 655, inclusive, is connected thruto relay 220. During the first twenty-four impulses, while the displaydrums of the indicators are stepped from 99 to 75, ground potential isconnected through contacts 503 and 57! and conductor 5?? to wiper 669,and also through the winding of relay 22c, conductor 223 and contacts584 and 516 to wiper 662. If the marking circuit of theengagedindicatons is not located in the contact banks associated withwiper 6G9 and wiper 662, then, on the twenty-fifth impulse when thewipers are again positioned on the first contacts of the banks,oiT-normal springs 65B are opened momentarily to disconnect theshortcircuit from across the winding of relay 570. Relay 51!} operatesin series with relay 6% over the following circuit: negative batterythru the winding of relay 6%, conductor $02, winding of relay 5m,conductor 579, contacts 501, conductor 6&3 and contacts 553 to ground.Relay 5w transfers ground from wiper 869 to wiper 668 at contacts 5?!and 5'32, transfers ground from wiper 562 to wiper 563 at contacts Elliand 515, and transfers the control circuit including the-oifnormalsprings from relay dill! to relay 623 at contacts 513 and 514. When thenext impulse is transmitted, oiT-normal springs completethe circuit fromground potential through contacts 5'53, conductor 66 contacts 6M and thewinding of relay 620 to negative battery. Relay i326 operates and atcontacts iiZl prepares the operating circuit for relay tilt which atthis time is shortcircuited at oiT-norrnal springs 650. If the mark-.ing circuit from the engaged indicators is not located in the contactbanks associated with wipers 5% and 6-33, at the end of the secondonehalf rveolution when the indicators display 50, relay tit operates ina manner similar to that previously described for relay 57d, transfersground from wiper 568 to wiper 667 at contacts 6H and 6E2, transfersground potential from wiper 553 to wiper 664 at contacts 656 and M5, 1

and transfers the controlling circuit from relay $26 to rela G453 atcontacts tit and 6M. At the beginning or the third one-half revolutionof the wipers, relay Mil operates and at contacts 66! prepares a circuitfor operating relay 63%. If it is assumed that 22 is to be displayed onthe indicators, the marking circuit is not encountered during the thirdone-half revolution and relay 83% operates and at contacts 63! and 632transfers ground potential from wiper 66? to wiper i5; and at contacts635 and 634 transfers ground potential from wiper 564 to wiper 6%.Providing the marking circuit of the selected indicators is connected tothe third contact of level 658, the

wipers are stepped until wiper 65S encounters the third bank contact atwhich time a circuit is completed from ground thru 632, wiper 5655,third contact of bank 656, conductor Hit, bank contact lei, wiper lt'i,conductor Hi3, wiper [953, of the reset selector, contacts lltl, lBl'andI65, conductor I69 and the winding of relay 250 to negative battery.Cut-oil relay 2H1 operates and at contacts 2!! closes the followingcircuit to operate relay 480 and to maintain impulsing relays 556 and5E6operated: negative battery thru the lower winding of relay 5%, lowerwindingaof relay 55d, conductor 554, lower winding of relay E30,conductor Q87, contacts 2i I, conductor 212, contacts H2, conductor Illand contacts 205to ground potential on conductor 289. Relay 480 operatesand opens the circuit to relay Hill at contacts 48 which restores andopens the im pulsing circuits to the indicators.

If the entire flight is displayed on the selected set of indicators, thecross-connecting conductor 748 would be connected to the third contactinlevel 555 rather than in level 556, and the marking circuit would becompleted from ground thru the winding of relay 228, conductor 223,contacts 564 and Eilii, conductor 585, contacts tliand 634, wiper s65,third contact of bank 655, conductor Mt, bank contact i il, wiper 73's,conductor [98, wiper lt ii, contacts ll i, I87 and [65, conductor H39and the winding of relay 2m to negative battery. Although relay 225would operate in series with relay 2 it, it performs no function at thistime.

Each of the engaged indicators now displays the number of seatsinitially available between two stops of the flight. Relays forcontrolling impulsing circuits are restored to normal, and the wipers ofthe reset connector are rotated to the next set of bank contacts toprepare impulsing circuits for the next set of space indicators that areto be reset as will now be described. Relay 38d operates, opens thelocking circuit of slowrelease relay did at contacts 33, opens thecircuits of relay 2% and the circuit of cut-in relay lot at contacts 48%as previously stated, at contacts idl closes its locking circuit throughconductor 83 to ground on wiper 66!, and at contacts 382 opens theenergizing circuit to the lower winding of relay 5%. Relays 259, inc and55% release followed by relay ili. Relay Hill opens the initialoperating circuit of relay 280 at contacts H2 and opens a circuit torelease relay lit at contacts Hi. Relays lit and I98 prepare thepreviously traced impulsing circuit for the rotary stepping magnet ofthe reset connector. Relay 5 56, at contacts 553 and 5M, transfers thecircuit including the oscillating penduluin from the impulsing relayssec and 560 to the open circuit of the pick-up relay 545i, closes apreviously traced circuit for maintaining relays 55d and 553d operatedat contacts and at contacts 5&2 opens a point in the previously tracediinpulsing circuit of switch S859. Upon releasing, relay tilt opens theenergizing circuit of slowreleasing relay 5 39 at contacts H2. After aninterval, relay 58B releases and at contacts 593 opens the energizingcircuit of relays 51G,- Silt, 6MB, 6%, E323, and EM, and prepares thecircuits of relays 32G, 33d, sec, 455, and 456 at contacts 5M, opens theenergizing circuit of relay 220 at contacts 5%, and at contacts 5%closes thefollowing circuit to return the wipers of switch 565$ to thenormal position on the first'bank contacts of the levels: ground thrucontacts of level 555i, wiper 66L interrupter contacts J6EE); conductor4%, contacts 5&6, conductor 642 and stepping magnet M655 to negativebattery. The switch steps in self-interrupting manner until wiper 5E!encounters the open circuit at the first contact of switch level E55.Also, at the first position, the locking circuit of relay 58a is opened.Relay 48E? releases and at contacts 84 closes the circuit for againoperating impulse-control relay ll'ilto start the previously describedsequence of operation to send. a single impulse to rotary magnet its;that is, relay 3H} releases, relay I60 operates, the wipers of the resetconnector are stepped rotary to the second set of contacts in the firstlevel, relay 200 operates, relay I10 releases, relay 3I8 operates, relayI60 releases, relays 240 and H operate over the busy lamp circuit of thesecond set of indicators, relays 250 and I00 operate, relay 280releases, and pick-up relay 540 operates to complete circuits forsending impulses to the second set of space indicators in the mannerpreviously described for the first set. The second set are all returnedto 99 and then switch S059 is again caused to operate to reset thesecond set of space indicators to the number indicating the number ofseats initially available. This system continues to operateautomatically in a manner similar to that previously described until allspace indicators which are connected in the first level of the engagedreset connector are each reset to display the number of seats initiallyavailable. On the eleventh rotary step of the reset connector, cam.springs CAM of the reset connector are closed to prepare the followingcircuit for relay I20: ground thru contacts 123, 122 and H1, conductor108, wiper I94, contacts I05, I23 and HI and winding of relay I20 tonegative battery. When relay I10 releases immediately after the wipersreach the eleventh position, the circuit is completed at contacts I'IIto operate relay I20. Relay I20 connects its energizing circuit toground conductor 288 at contacts I24, opens its initial energizingcircuit at contacts I23, opens an additional point in the circuit ofimpulsing relay 3H) at contacts I21, prepare a circuit for relay E10including interrupter springs 128 of vertical magnet 130 at contactsI29, opens a point in the operating circuit of relay 240 at contactsI28, completes a circuit for operating release magnet 139 at contactsI25, and at contacts i22 transfers the closed impulsing circuit fromrotary magnet 138 to vertical magnet 130. The circuit for operating therelease magnet 139 may be traced from negative battery thru the windingof release magnet 139, contacts 1I9, conductor 185, wiper I95, contactsI8I, I25 and I05, wiper I94, conductor 104 and contacts H1, 122 and 123to ground. The circuit closed at contacts I22 to partially energizevertical magnet 138 is as follows: negative battery thru contacts 3II,conductor 3I5, contacts 21I, 265 and 25I, conductor 251, relay I80,contacts I5I, I4I, I32, I22 and HM, wiper I8I, conductor 10I, contactsIII, vertical magnet 130, and resistor 125 to ground, the R. O. N.contacts 120 being open at this time. When the release magnet operates,the wipers 13I to 131 return in the well known manner to the normalrotary position while the partial energization of the vertical steppingmagnet positions the vertical pawl against the vertical ratchet tomaintain the wipers at the same level upon clearing the switch banks.Also, when the wipers begin their rotaryreturn action, cam springs CAMare actuated to open, at contacts 123, the energizing circuit of therelease magnet 138. As the wipers move from rotary position 1 to thenormal rotary position, rotary off-normal springs R. O. N. are actuatedto close, at contacts 120, a short-circuit across resistor 125, thus toincrease the current flow in the winding of vertical stepping magnet130.

The wipers are stepped vertically one step to the second level andvertical interrupter springs 125 operate to close the following circuitfor operating relay I10: ground thru contacts 126, conductor I08, wiperI98, contacts I29 and I86 and relay I10 to negative battery. Relay I10,at contacts I1I, opens the circuit of relay I20 which, upon releasing,opens the energizing circuit of vertical magnet 130 at contacts I22 andcloses the previously traced circuit at contacts I2I to energize rotarymagnet 138. The wipers are stepped to the first bank contacts of thesecond level. When the vertical magnet is deenergized, the circuit ofslow-releasing relay I10 is opened at vertical interrupter springcontacts 126; and upon releasing relay I10 recloses the energizingcircuit of impulsing relay 3I0 at contacts I12. The rotary steppingmagnet 138 is deenergized. The sequence of operations for resetting thespace indicators that are connected in the second level of bank contactscontinues in the same manner as previously described for resetting theindicators connected on the first level. Also, the indicators connectedin the remaining eight levels are reset in a similar manner.

After all the indicators that are accessible to the reset connector ofFigure 7 have been reset, the wipers I9I to I98 of the reset selectorFigure 1 are rotated to the next set of bank contacts to connect withanother reset connector as will now be explained. When the wipers 13I to131 of the previously selected reset connector are stepped to the tenthlevel of bank contacts, normal post springs N. P. S. are actuated toopen contacts 122 and to close contacts 12I. On the eleventh rotary stepon this tenth level the CAM springs are operated. The operation of theCAM springs closes a circuit from ground thru contacts 123, 12I and H5,conductor 106, wiper I85, contacts I08 and I13 and lower winding ofrelay I to negative battery. Relay I80 operates and closes the followinglocking circuit to hold itself operated until the wipers of the resetconnector have returned to normal: negative battery thru contacts I83,wiper I83, conductor 103 and contacts 124 of vertical off-normal springsV. O. N. to ground.

During its operation, relay I80 releases transfer relays I30 and I40 atcontacts I84, opens the energizing circuit of slow-acting relay 200 atcontacts I85, opens a point in the circuit of slow-releasing relay I10at contacts I86, opens a point in the operating circuit of relay 2I0 atcontacts I81 and prepares a circuit for operating the release magnet 139of the reset connector at contacts I82.

Relay I40 restores and reconnects the impulsing circuit which iscontrolled by relay 3 I 0 to the rotary magnet I99 of the reset selectorat contacts I48, and at contacts I41 opens a point in the operatingcircuit of relay 480. Relay I10 releases, relay 3I0 operates, and relayI60 releases in the manner previusly described. When relay I00 releases,the circuit for operating release magnet 139 is closed from negativebattery thru the winding of release magnet 139, contacts 1I9, conductor185, wiper I95, contacts I82, conductor I16, contacts 202, conductor I51and contacts I82 to ground. When wipers 13I to 131 return to theirnormal position, vertical off-normal springs V. O. N. are actuated toopen, at contacts 124, the holding circuit of relay I80. Relay I80restores and at contacts I82 opens the energizing circuit of releasemagnet 139, and at contacts I88 recloses the operating circuit of relayI10. The operation of relay I10 starts the previously described sequenceof operations for energizing rotary magnet I99 to thereby step wipersI9I to I98 to the second set of contacts of the previously selectedlevel. The reset converter continues its operation and controls thenewly selected reset connector and its associated space indicators inexactly the same manner as previously described for controlling thereset connector of Figure 7 and its associated space indicators. Afterthe space indicators that are comiected to the second reset connectorare reset to show the initially available seating space, other resetconnectors, similar to Reset Connector, Figure '7, that are of the samedate and that are connected in the same level in the contact of thereset selector are selected automatically in sequence, and thereby allspace indicators for one date are automatically reset.

After all indicators for a date have been reset, audible and visualsignals are given until the Date Reset key is restored manually toreturn all converted circuits to normal as will now be explained. Aswipers [9| to I98 more off the tenth set of contacts when the resettingoperation has been completed, cam springs CAM of the selector areactuated to connect in series relays I86 and 260 in the followingcircuit to operate release relay 2M! only; negative battery thru theupper winding of relay Est, conductor H5, contacts 238 of cam springsCAM, upper winding of relay 260 and contacts 299 of vertical oil-normalsprings V. O. N. to ground. Relay 260 closes its locking circuit andalso closes a circuit for illuminating signal lamp 345 at contacts 25:,removes ground from holding conductor 289 at contacts 262, places groundon conductor 268 to operate an audible signalling device (not shown) atcontacts 254, opens a point in the impulsing circuit at contacts 265 andcloses the following circuit at contacts 259 to operate release magnetIll: ground thru contacts 269, conductor I18, contacts I89 and thewinding of release magnet ill to negative battery. In response to theoperation of the release magnet, wipers TEN and H38 return to normal,and cam springs CAM and vertical ofi-normal springs V. O. N. are thenactuated to open contacts 2&8 and 2%, respectively. The removal ofground from conductor 2% stops the operation of vibrator 53d, removesthe bias from relays 368, 319, 389, 566, and did, and releases relayslet, 3653, 32c, 52d, 55%), and 56' Relay 3% opens the energizing circuitof relay He at contacts 367, relay 3% opens a circuit to release relay3% at contacts 32 l, and relay 52% opens the energizing circuit of relay5!!) at contacts 5 26. Upon observing the audible and visual signals forindicating the completion of the resetting operation, the operatorrestores the Date Reset key which opens a circuit to release relay ill}at contacts 232, and opens the locking circuit of relay 2 5i; and alsoopens a circuit to extinguish lamp 345 at contacts 233. Relay 266restores and opens the circuit of release magnet Ill at contacts 26?]and opens the circuit of the audible signal device at contacts Ed t.This completes the restoration of the reset converter.

To reset the indicators that correspond to only one flight of aparticular date, the Flight Resetkey is operated and then four digitsare dialed. The first digit, which corresponds to the date, determinesthe level to which the wipers of the reset selector are stepped; thesecond digit, which is the first digit of the flight number, controlsthe rotary stepping of the reset selector; and the remaining two digits,which are the last two digits of the fiightnumber, control the verticaland rotary stepping of the selected connector.

The operation of the Flight Reset key closes a circuit from ground atcontacts 235 to holding conductor 285i, and at contacts 234. prepares anoperating circuit for relay 280. In response to the application ofground potential to conductor 289, the circuits are completed aspreviously described to enerzige the biasing windings of relays 360,375i, 330, 400 and M0; to operate relays 526, bit, 550 and 568, to startvibrator 5st, and to operate impulsing relay 3H]. Relay 3K3 completes acircuit to illuminate lamp 332 and also prepares the alarm circuit aspreviously described at contacts 313, and completes the followingcircuit to operate flight reset relay 2% at contacts 3l2: negativebattery thru contacts 3l'2, conductor 238, contacts 283, lower windingof relay 286 and contacts 234 to ground. Relay 28d prepares theimpulsing circuit at contacts 28 l completes its locking circuit atcontacts 282, opens its initial energizing circuit at contacts 283,prepares a release circuit at contacts 235 including the upper windingof release relay 260 and the upper winding of relay 236, opens a pointin a subsequently described operating circuit of release relay 2% atcontacts 235, connects the lower winding of trouble relay 358' toconductor 21'! at contacts 28%, prepares a circuit for operating relaysec at contacts 283 and opens a point in the circuit to vertical wiper338 at contacts 28?.

Upon operating, flight reset relay 280 does not prepare certainpreviously described busy circuits that are prepared when date resetrelay 2T5 is operated. Since the operating circuit of relay 326 nowremains open at contacts 216 of relay 210, relay 326 is not operated aspreviously described. Therefore, the circuits of level busy relay, suchas relay 390, are not prepared, and the relays remain unoperated topermit regular selectors to have access to indicators that are in thesame date group as that selected by the reset selector. Furthermore,since the circuit of busy-guard relay 250 is open at contacts 287, thecircuit arrangement for delaying the rotary operation of the resetselector while any flight selector corresponding to the selected date isengaged, is inefiective.

After operating the Flight Reset key, the operator manipulates the dialto transmit the first digit. The wipers Till to 168 are raised to thelevel corresponding to the digit dialed, and relays IGIJ and 2% areoperated in the manner previously described. The impulsing circuitdiffers from the circuit previously traced for operating the verticalmagnet only in that the circuit now includes contacts 23E rather thancontacts 21!. At the conclusion of the series of im pulses,slow-releasing relay 96E releases and then relay 2% releases to operatetransfer relay in the manner described for the date resetting operation.The operation of the reset converter at this time difiers from that ofthe previous description in that the open circuit at contacts 2%prevents the automatic operation of impulsing relay 318.

In response to dialing the second digit, rotary magnet we steps wipersml to Hit to the set of contacts for seizing the desired resetconnector, for example. he Reset Connector of Figure 7. Upon releasingatthe conclusion of the second digit, relays I66 and 268 complete theoperation of transfer, relay I45, which connects the impulsing circuitto vertical magnet 13B.

Vertical magnet 13% of the reset connector receives the third series ofdialed. impulses to raise wipers T3! toit] to the level corresponding tothe third digit dialed.

Transfer relay l 39 operates at the conclusion of the transmission ofthe third digit in the 19 manner previously described and, in additionto transferring the impulsing circuit to the rotary magnet 138, preparesa circuit for operating relay 380 at contacts 536.

When the fourth digit is dialed, rotary magnet 538 is energized to stepthe rotary wipers to a corresponding set of bank contacts, the set beingconnected to space indicators that are to be reset. When relay I60releases but before relay Zfifi releases the following circuit is closedto operate relay 300: negative battery thru the winding of relay 30G,conductor 3", contacts I36, conductor 318, contacts 288, conductor 3,contacts 3535, conductor 266, contacts 254 and 2M, conductor i8? andcontacts I62 to ground. Relay 3G9 transfers its operating circuit toholding conductor 289 at contacts 304, disconnects the initialcontrolling circuit from impulsing relay 310 at contacts 308 andconnects a previously traced circuit which is controlled by relay I10 atcontacts 38!, closes a previously traced locking circuit for maintainingrelay 2B9 operated at contacts 393, and prepares an operating circuitfor relay H at contacts Bill.

If the selected space indicators, as illustrated in Figure 8, areengaged by a regular connector, negative battery is applied to conductorH6 through circuits of the regular connector. The negative batteryapplied through the regular connector circuits shunts relay 240 and thusprevents its immediate operation. When the mdicators are no longerengaged by the regular reset connectors, relay 240 operates over thepreviously traced circuit including the busy lamp 850 and ground. Theresetting operation continues exactly as previously described until allspace indicators of the selected flight are reset to read the initialspaces available.

When all the indicators of the flight have been reset, relay 220 isoperated as previously described. However, now relay 220, at contacts222, completes the release circuit which has been prepared at contacts284 of flight reset relay 280. Relays I88 and 23S operate over thefollowing circuit: negative battery thru the upper winding of relay 98D,conductor I15, contacts 222. upper winding of relay 230, contacts 284,conductor 2G9, wiper Hi3, conductor 103 and contacts 124 of verticalofi-normal springs V. O. N. to ground. Release rela-y 26B isshort-circuited to prevent its operation until the connector has restored to normal. Relay I80 closes an obvious locking circuit toconductor 209 at contacts I83, opens an additional point in the circuitof release magnet ill at contacts I89 and completes a previously tracedcircuit for opera-ting release magnet I33 at contacts I82. Relay 230closes a circuit to ensure the subsequent operation of relay 266 atcontacts 23!. When wipers T3! to 131 of the reset connector return tonormal, vertical ofi-normal springs V. O. N. are actuated for openingcontacts 124 to thereby remove the short-circuit from relay 260. Sincerelay I80 has a low resistance upper winding, it may not remain operatedthrough the circuit which includes the relatively high resistance of theupper winding of relay 280. In response to the opening of theshort-circuit, the following circuit is effective to operate relay 250:ground thru contacts 29E) of the selector vertical off-normal springs,upper winding of relay 260, contacts 284 and 21H and the lower windingof relay 230 to negative battery. Upon operating, relay 260 closescircuits for signalling the operator as explained above, closes thecircuit to release mags net I'll at contacts 268, and by removing groundfrom holding conductor 289 at contacts 262 causes the release of relaysas previously described. When the operator restores the Flight Resetkey, the energizing circuit of relay 280 is opened at contacts 234 andthe circuit to restore relay 260 and also to extinguish lamp 346 isopened at contacts 235. Relay 26!! opens the circuit of release magnetITI at contacts 269 and opens the circuit of the audible signal deviceat contacts 264 to indicate that all circuits of the reset converter arerestored to normal.

While there has been described what is at present considered to be thepreferred embodiment of the invention, it will be understood thatvarious modifications may be made therein, and it is intended to coverin the appended claims all such modifications as fall within the truespirit and scope of the invention.

Having described my invention in detail, what I claim and desire to haveprotected by issuance of Letters Patent of the United States is:

1. In an indicating system, a plurality of indicators each having aplurality of positions and each having a means for operating itindividually, control means common to all of said indicator operatingmeans for operating said means simultaneously, means associated witheach of said indicators and each operated responsive to movement of itsassociated indicator in a restoring operation to an identicalpredetermined position for disabling the indicator operating meansassociated therewith to thereby stop the restoring movement of theassociated indicator, restoring means common to all of said disablingmeans and operated thereby only in response to all of said disablingmeans being operated during said restoring operation to restore saiddisabling means to thereby enable all of said indicator operating meansfor a resetting operation, said control means again operating all ofsaid indicator operating means in a resetting operation to move all saidindicators simultaneously, and means common to all said indicators fordisabling all of said indicator operating means simultaneously duringthe resetting operation when all said indicators have eachsimultaneously reached a second identical predetermined position.

2. In an indicating system, a plurality of stepby-step indicators eachhaving a plurality of positions and each having impulsing means forstepping it individually responsive to impulses, control means common toall of said impulsing means for transmitting impulses to said impulsingmeans for stepping said indicators simultaneously, means associated withsaid indicators and each operated responsive to the stepping of itsassociated indicator in a restoring operation to an identicalpredetermined position for disabling said impulsing means associatedtherewith to thereby stop the stepping of the associated indicator forsuch restoring operation, restoring means common to all of saiddisabling means and operated thereby only in response to all of saiddisabling means being operated during said restoring operation torestore said disabling means to thereby enable all of said impulsingmeans for a resetting operation, said control means transmittingimpulses to said impulsing means to again step said indicatorssimultaneously in a resetting operation, and means common to all saidindicators for disabling all of said impulsing means simultaneouslyduring the re- 1 setting operation when all said indicators have 21 eachsimultaneously steppedtoa certain identical predetermined position.

3. In an indicating system, a plurality of indicators each havingapluralityor positions including a normal position and each havingameans for operating itindividually, a switch having a plurality ofpositions including a normal position each corresponding to a positionof the indicators, control means common to said indicator operatingmeans for operating said means simultaneously to thereby move said.indicators simultaneously in a restoring operation, disabling meansassociated with said indicators, each of said disabling means operatedduring its restoring movement in response to its associated indicatorreaching its normal position for disabling the indicator operating meansassociated therewith to thereby stop the restoring movement of theassociated indicator, normally disabled means for operating said switchunder control of said control restoring means, means common to all ofsaid disabling means and operated thereby only in response to all ofsaid disabling means being operated by all said indicators reachingtheir normal positions to restore said disabling means to thereby enableall of said indicator operating means for a resetting operation and toalso enable said normally disabled switch operating means, said controlmeans again operating all of said indicator operating means and alsooperating said switch operating means to move said indicators in aresetting operation from said normal position and said switch in ahunting operation from its normal position simultaneously, means commonto said indicators for disabling all of said indicator operating meanssimultaneously during the resetting operation, and means controlled bysaid switch reaching a predetermined position in its hunting operationfor operating said common disabling meansto thereby simultaneously stopsaid indicators in their resetting operations at their correspondingpositions,

4. In an indicating system, a plurality of indicators each having aplurality of positions to which it may be stepped and each having anindividual pulsing circuit for stepping each indicator responsive toreceived impulses, a plurality of cut-oif relays corresponding in numberto said indicators, one of said cut-oil relays being associated witheach individual pulsing circuit, a sender including means forsimultaneously transmitting pulses over said individual pulsing circuitsto simultaneously step said indicators in a restoring operation, meansfor operating each cut-off relay in response to its correspondingindicator reaching a predetermined position in its restoring operation,means controlled by each operated cut-off relay for opening itscorresponding pulsing circuit to step further stepping or" thecorresponding indicator in its restoring operation, an automatic switchoperative responsive to impulses, a normally open pulsing circuit foroperating said switch controlled. by said sender, means operated aftersaid restoring operations in response to op eration of the last of thecut-ofif relays operated for restoring said cut-off relays to recloseall of said individual pulsing circuits for a resetting operation andfor closing normally open switch pulsing circuit to simultaneouslytransmit impulses from said sender to said indicators over theirindividual pulsing circuits and to said automatic switch over itspulsing circuit to thereby step said indicators in a resetting operationand said switch simultaneously, and means associated with said switchfor determining the number of simultaneous. steps to: be taken by saidindicators and said switch inthe resetting operation of said indicatorsfrom said predetermined position.

5,. An indicating system as claimed in claim 4 wherein said determiningmeans includes marking conductors cross-connected from saidindicatorstosaid switch and closed at predetermined positions of saidswitch, in accordance with the number of steps to be taken by theindicators in stepping from their predetermined positions to their newreset positions.

6. In an indicating system, a plurality of groups of indicators includedin a large group, each indicator having a plurality of positions andeach having a means for operating it individually, the groups beingarranged in a predetermined order in said large group, selecting meansfor opera tively selecting successive ones of said groups in said order,control means associated with said selecting means common to all of saidindicator operating means of a selected indicator group for operatingall said selected group indicator operating means simultaneously in arestoring movement, disabling means associated with said indicators andeach operated responsive to said restoring movement of its associatedindicator to a predetermined position for disabling the indicatoroperating means associated therewith to thereby stop the restoringmovement of the associated indicator, restoring means common to all ofsaid disabling means and operated thereby only in response to all ofsaid disabling means being operated during said restoring movement torestore said disabling means to thereby enable all of said selectedindicator operating means for a resetting operation, said control meansagain operating all of said selected indicator operating means in aresetting operation to move all said selected indicators simultaneously,meanscommon to all said indicators for disabling all of said selectedindicator operating means simultaneously when said selected indicatorshave simultaneously reached a second predetermined position in saidresetting operation, and means oper ated responsive to said commondisabling means for then automatically operating said selecting means tooperatively select the next successive group of indicators in said orderin said large grou 7. In an indicating system, an indicator having aplurality of positions including a normal position, means for operatingsaid indicator from each position to the next, a stepping switchincluding a plurality of sets of contacts, said switch having aplurality of positions including a normal position correspondingrespectively to said indicator positions, a different set of contactsbeing actuated by said switch in each different position thereof,control means for operating said indicator operating means to move saidindicator in a restoring movement, means associated with said indicatorand operated responsive to said indicator reaching its normal positionfor causing said switch to be moved under control of said control means,said indicator and said switch being moved from their normal positionsin step in a resetting movement, and means operated responsive toactuator of a designated set of contacts by said switch when moved tothe corresponding position for removing said indicator from control ofsaid control means to thereby stop said indicator resetting movement inits corresponding position.

8. In an indicating system as claimed in claim 7, means operatedresponsive to movement of said 23 24 switch to the positioncorresponding to said desig- Number Name Date nated set of contacts forcausing said switch to 1,958,208 Scheidegger May 8, 1934 stepautomatically to its normal position. 1,967,331 Smith July 24, 19342,076,672 Robinson Apr. 13, 1937 References Cited in the file of thispatent 5 2,103,297 Nelson ,23, 1937 2,248,820 Haselton July 8, 1941UNITED STATES PATENTS Number Name Date 1,852,994 Frischknecht Apr. 5,1932

